Karol Beck (born April 3, 1982 in Zvolen) is a male tennis player from Slovakia, who turned professional in 2001. He has been ranked as high as 36th in the world (August 22, 2005).
On October 25, 2004, Beck lost in the final of the St. Petersburg Open to Mikhail Youzhny, 6–2, 6–2.
On February 13, 2006 the International Tennis Federation (ITF) announced Beck had tested positive for the beta agonist clenbuterol during the 2005 Davis Cup semifinal for Slovakia against Argentina, which Slovakia won 4–1. As a consequence, the ITF suspended him from the game for two years until October 31, 2007.